/*
 * exp golomb vlc stuff
 * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
 * Copyright (c) 2004 Alex Beregszaszi
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * @brief
 *     exp golomb vlc stuff
 * @author Michael Niedermayer <michaelni@gmx.at> and Alex Beregszaszi
 */

#ifndef AVCODEC_GOLOMB_H
#define AVCODEC_GOLOMB_H

#include <stdint.h>

#include "libavcodec/get_bits.h"
#include "libavcodec/put_bits.h"
#include "libavformat/avio.h"
#define INVALID_VLC           0x80000000
extern "C"
{
    extern const uint8_t ff_golomb_vlc_len[512];
    extern const uint8_t ff_ue_golomb_vlc_code[512];
    extern const  int8_t ff_se_golomb_vlc_code[512];
    extern const uint8_t ff_ue_golomb_len[256];

    extern const uint8_t ff_interleaved_golomb_vlc_len[256];
    extern const uint8_t ff_interleaved_ue_golomb_vlc_code[256];
    extern const  int8_t ff_interleaved_se_golomb_vlc_code[256];
    extern const uint8_t ff_interleaved_dirac_golomb_vlc_code[256];


    /**
     * read unsigned exp golomb code.
     */
    static inline int get_ue_golomb(GetBitContext *gb)
    {
        unsigned int buf;

        OPEN_READER(re, gb);//  unsigned int name ## _index = (gb)->index;  re_index = 1; //unsigned int av_unused name ## _cache;  re_cache
        UPDATE_CACHE(re, gb);
        buf = GET_CACHE(re, gb);

        if (buf >= (1 << 27))
        {
            buf >>= 32 - 9;
            LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
            CLOSE_READER(re, gb);

            return ff_ue_golomb_vlc_code[buf];
        }
        else
        {
            int log = 2 * av_log2(buf) - 31;
            LAST_SKIP_BITS(re, gb, 32 - log);
            CLOSE_READER(re, gb);
            if (CONFIG_FTRAPV && log < 0)
            {
                //av_log(NULL, AV_LOG_ERROR, "Invalid UE golomb code\n");
                return AVERROR_INVALIDDATA;
            }
            buf >>= log;
            buf--;

            return buf;
        }
    }

    /**
     * Read an unsigned Exp-Golomb code in the range 0 to UINT32_MAX-1.
     */
    static inline unsigned get_ue_golomb_long(GetBitContext *gb)
    {
        unsigned buf, log;

        buf = show_bits_long(gb, 32);
        log = 31 - av_log2(buf);
        skip_bits_long(gb, log);

        return get_bits_long(gb, log + 1) - 1;
    }

    /**
     * read unsigned exp golomb code, constraint to a max of 31.
     * the return value is undefined if the stored value exceeds 31.
     */
    static inline int get_ue_golomb_31(GetBitContext *gb)
    {
        unsigned int buf;

        OPEN_READER(re, gb);
        UPDATE_CACHE(re, gb);
        buf = GET_CACHE(re, gb);

        buf >>= 32 - 9;
        LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
        CLOSE_READER(re, gb);

        return ff_ue_golomb_vlc_code[buf];
    }

    static inline unsigned svq3_get_ue_golomb(GetBitContext *gb)
    {
        uint32_t buf;

        OPEN_READER(re, gb);
        UPDATE_CACHE(re, gb);
        buf = GET_CACHE(re, gb);

        if (buf & 0xAA800000)
        {
            buf >>= 32 - 8;
            LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
            CLOSE_READER(re, gb);

            return ff_interleaved_ue_golomb_vlc_code[buf];
        }
        else
        {
            unsigned ret = 1;

            do
            {
                buf >>= 32 - 8;
                LAST_SKIP_BITS(re, gb,
                               FFMIN(ff_interleaved_golomb_vlc_len[buf], 8));

                if (ff_interleaved_golomb_vlc_len[buf] != 9)
                {
                    ret <<= (ff_interleaved_golomb_vlc_len[buf] - 1) >> 1;
                    ret  |= ff_interleaved_dirac_golomb_vlc_code[buf];
                    break;
                }
                ret = (ret << 4) | ff_interleaved_dirac_golomb_vlc_code[buf];
                UPDATE_CACHE(re, gb);
                buf = GET_CACHE(re, gb);
            }
            while (ret < 0x8000000U && BITS_AVAILABLE(re, gb));

            CLOSE_READER(re, gb);
            return ret - 1;
        }
    }

    /**
     * read unsigned truncated exp golomb code.
     */
    static inline int get_te0_golomb(GetBitContext *gb, int range)
    {
        av_assert2(range >= 1);

        if (range == 1)
            return 0;
        else if (range == 2)
            return get_bits1(gb) ^ 1;
        else
            return get_ue_golomb(gb);
    }

    /**
     * read unsigned truncated exp golomb code.
     */
    static inline int get_te_golomb(GetBitContext *gb, int range)
    {
        av_assert2(range >= 1);

        if (range == 2)
            return get_bits1(gb) ^ 1;
        else
            return get_ue_golomb(gb);
    }

    /**
     * read signed exp golomb code.
     */
    static inline int get_se_golomb(GetBitContext *gb)
    {
        unsigned int buf;

        OPEN_READER(re, gb);
        UPDATE_CACHE(re, gb);
        buf = GET_CACHE(re, gb);

        if (buf >= (1 << 27))
        {
            buf >>= 32 - 9;
            LAST_SKIP_BITS(re, gb, ff_golomb_vlc_len[buf]);
            CLOSE_READER(re, gb);

            return ff_se_golomb_vlc_code[buf];
        }
        else
        {
            int log = av_log2(buf), sign;
            LAST_SKIP_BITS(re, gb, 31 - log);
            UPDATE_CACHE(re, gb);
            buf = GET_CACHE(re, gb);

            buf >>= log;

            LAST_SKIP_BITS(re, gb, 32 - log);
            CLOSE_READER(re, gb);

            sign = -(buf & 1);
            buf  = ((buf >> 1) ^ sign) - sign;

            return buf;
        }
    }

    static inline int get_se_golomb_long(GetBitContext *gb)
    {
        unsigned int buf = get_ue_golomb_long(gb);
        int sign = (buf & 1) - 1;
        return ((buf >> 1) ^ sign) + 1;
    }

    static inline int svq3_get_se_golomb(GetBitContext *gb)
    {
        unsigned int buf;

        OPEN_READER(re, gb);
        UPDATE_CACHE(re, gb);
        buf = GET_CACHE(re, gb);

        if (buf & 0xAA800000)
        {
            buf >>= 32 - 8;
            LAST_SKIP_BITS(re, gb, ff_interleaved_golomb_vlc_len[buf]);
            CLOSE_READER(re, gb);

            return ff_interleaved_se_golomb_vlc_code[buf];
        }
        else
        {
            int log;
            LAST_SKIP_BITS(re, gb, 8);
            UPDATE_CACHE(re, gb);
            buf |= 1 | (GET_CACHE(re, gb) >> 8);

            if ((buf & 0xAAAAAAAA) == 0)
                return INVALID_VLC;

            for (log = 31; (buf & 0x80000000) == 0; log--)
                buf = (buf << 2) - ((buf << log) >> (log - 1)) + (buf >> 30);

            LAST_SKIP_BITS(re, gb, 63 - 2 * log - 8);
            CLOSE_READER(re, gb);

            return (signed) (((((buf << log) >> log) - 1) ^ -(buf & 0x1)) + 1) >> 1;
        }
    }

    static inline int dirac_get_se_golomb(GetBitContext *gb)
    {
        uint32_t ret = svq3_get_ue_golomb(gb);

        if (ret)
        {
            int sign = -get_bits1(gb);
            ret = (ret ^ sign) - sign;
        }

        return ret;
    }

    /**
     * read unsigned golomb rice code (ffv1).
     */
    static inline int get_ur_golomb(GetBitContext *gb, int k, int limit,
                                    int esc_len)
    {
        unsigned int buf;
        int log;

        OPEN_READER(re, gb);
        UPDATE_CACHE(re, gb);
        buf = GET_CACHE(re, gb);

        log = av_log2(buf);

        if (log > 31 - limit)
        {
            buf >>= log - k;
            buf  += (30U - log) << k;
            LAST_SKIP_BITS(re, gb, 32 + k - log);
            CLOSE_READER(re, gb);

            return buf;
        }
        else
        {
            LAST_SKIP_BITS(re, gb, limit);
            UPDATE_CACHE(re, gb);

            buf = SHOW_UBITS(re, gb, esc_len);

            LAST_SKIP_BITS(re, gb, esc_len);
            CLOSE_READER(re, gb);

            return buf + limit - 1;
        }
    }

    /**
     * read unsigned golomb rice code (jpegls).
     */
    static inline int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit,
                                           int esc_len)
    {
        unsigned int buf;
        int log;

        OPEN_READER(re, gb);
        UPDATE_CACHE(re, gb);
        buf = GET_CACHE(re, gb);

        log = av_log2(buf);

        if (log - k >= 32 - MIN_CACHE_BITS + (MIN_CACHE_BITS == 32) &&
                32 - log < limit)
        {
            buf >>= log - k;
            buf  += (30U - log) << k;
            LAST_SKIP_BITS(re, gb, 32 + k - log);
            CLOSE_READER(re, gb);

            return buf;
        }
        else
        {
            int i;
            for (i = 0; i < limit && SHOW_UBITS(re, gb, 1) == 0; i++)
            {
                if (gb->size_in_bits <= re_index)
                    return -1;
                LAST_SKIP_BITS(re, gb, 1);
                UPDATE_CACHE(re, gb);
            }
            SKIP_BITS(re, gb, 1);

            if (i < limit - 1)
            {
                if (k)
                {
                    if (k > MIN_CACHE_BITS - 1)
                    {
                        buf = SHOW_UBITS(re, gb, 16) << (k - 16);
                        LAST_SKIP_BITS(re, gb, 16);
                        UPDATE_CACHE(re, gb);
                        buf |= SHOW_UBITS(re, gb, k - 16);
                        LAST_SKIP_BITS(re, gb, k - 16);
                    }
                    else
                    {
                        buf = SHOW_UBITS(re, gb, k);
                        LAST_SKIP_BITS(re, gb, k);
                    }
                }
                else
                {
                    buf = 0;
                }

                CLOSE_READER(re, gb);
                return buf + (i << k);
            }
            else if (i == limit - 1)
            {
                buf = SHOW_UBITS(re, gb, esc_len);
                LAST_SKIP_BITS(re, gb, esc_len);
                CLOSE_READER(re, gb);

                return buf + 1;
            }
            else
                return -1;
        }
    }

    /**
     * read signed golomb rice code (ffv1).
     */
    static inline int get_sr_golomb(GetBitContext *gb, int k, int limit,
                                    int esc_len)
    {
        unsigned v = get_ur_golomb(gb, k, limit, esc_len);
        return (v >> 1) ^ -(v & 1);
    }

    /**
     * read signed golomb rice code (flac).
     */
    static inline int get_sr_golomb_flac(GetBitContext *gb, int k, int limit,
                                         int esc_len)
    {
        unsigned v = get_ur_golomb_jpegls(gb, k, limit, esc_len);
        return (v >> 1) ^ -(v & 1);
    }

    /**
     * read unsigned golomb rice code (shorten).
     */
    static inline unsigned int get_ur_golomb_shorten(GetBitContext *gb, int k)
    {
        return get_ur_golomb_jpegls(gb, k, INT_MAX, 0);
    }

    /**
     * read signed golomb rice code (shorten).
     */
    static inline int get_sr_golomb_shorten(GetBitContext *gb, int k)
    {
        int uvar = get_ur_golomb_jpegls(gb, k + 1, INT_MAX, 0);
        return (uvar >> 1) ^ -(uvar & 1);
    }

#ifdef TRACE

    static inline int get_ue(GetBitContext *s, const char *file, const char *func,
                             int line)
    {
        int show = show_bits(s, 24);
        int pos  = get_bits_count(s);
        int i    = get_ue_golomb(s);
        int len  = get_bits_count(s) - pos;
        int bits = show >> (24 - len);

        print_bin(bits, len);

        //av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d ue  @%5d in %s %s:%d\n",
        bits, len, i, pos, file, func, line);

        return i;
    }

    static inline int get_se(GetBitContext *s, const char *file, const char *func,
                             int line)
    {
        int show = show_bits(s, 24);
        int pos  = get_bits_count(s);
        int i    = get_se_golomb(s);
        int len  = get_bits_count(s) - pos;
        int bits = show >> (24 - len);

        print_bin(bits, len);

        //av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d se  @%5d in %s %s:%d\n",
        bits, len, i, pos, file, func, line);

        return i;
    }

    static inline int get_te(GetBitContext *s, int r, char *file, const char *func,
                             int line)
    {
        int show = show_bits(s, 24);
        int pos  = get_bits_count(s);
        int i    = get_te0_golomb(s, r);
        int len  = get_bits_count(s) - pos;
        int bits = show >> (24 - len);

        print_bin(bits, len);

        //av_log(NULL, AV_LOG_DEBUG, "%5d %2d %3d te  @%5d in %s %s:%d\n",
        bits, len, i, pos, file, func, line);

        return i;
    }

#define get_ue_golomb(a) get_ue(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#define get_se_golomb(a) get_se(a, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#define get_te_golomb(a, r)  get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)
#define get_te0_golomb(a, r) get_te(a, r, __FILE__, __PRETTY_FUNCTION__, __LINE__)

#endif /* TRACE */

    /**
     * write unsigned exp golomb code.
     */
    static inline void set_ue_golomb(PutBitContext *pb, int i)
    {
        av_assert2(i >= 0);

        if (i < 256)
            put_bits(pb, ff_ue_golomb_len[i], i + 1);
        else
        {
            int e = av_log2(i + 1);
            put_bits(pb, 2 * e + 1, i + 1);
        }
    }

    /**
     * write truncated unsigned exp golomb code.
     */
    static inline void set_te_golomb(PutBitContext *pb, int i, int range)
    {
        av_assert2(range >= 1);
        av_assert2(i <= range);

        if (range == 2)
            put_bits(pb, 1, i ^ 1);
        else
            set_ue_golomb(pb, i);
    }

    /**
     * write signed exp golomb code. 16 bits at most.
     */
    static inline void set_se_golomb(PutBitContext *pb, int i)
    {
#if 0
        if (i <= 0)
            i = -2 * i;
        else
            i = 2 * i - 1;
#elif 1
        i = 2 * i - 1;
        if (i < 0)
            i ^= -1;    //FIXME check if gcc does the right thing
#else
        i  = 2 * i - 1;
        i ^= (i >> 31);
#endif
        set_ue_golomb(pb, i);
    }

    /**
     * write unsigned golomb rice code (ffv1).
     */
    static inline void set_ur_golomb(PutBitContext *pb, int i, int k, int limit,
                                     int esc_len)
    {
        int e;

        av_assert2(i >= 0);

        e = i >> k;
        if (e < limit)
            put_bits(pb, e + k + 1, (1 << k) + av_mod_uintp2(i, k));
        else
            put_bits(pb, limit + esc_len, i - limit + 1);
    }

    /**
     * write unsigned golomb rice code (jpegls).
     */
    static inline void set_ur_golomb_jpegls(PutBitContext *pb, int i, int k,
                                            int limit, int esc_len)
    {
        int e;

        av_assert2(i >= 0);

        e = (i >> k) + 1;
        if (e < limit)
        {
            while (e > 31)
            {
                put_bits(pb, 31, 0);
                e -= 31;
            }
            put_bits(pb, e, 1);
            if (k)
                put_sbits(pb, k, i);
        }
        else
        {
            while (limit > 31)
            {
                put_bits(pb, 31, 0);
                limit -= 31;
            }
            put_bits(pb, limit, 1);
            put_bits(pb, esc_len, i - 1);
        }
    }

    /**
     * write signed golomb rice code (ffv1).
     */
    static inline void set_sr_golomb(PutBitContext *pb, int i, int k, int limit,
                                     int esc_len)
    {
        int v;

        v  = -2 * i - 1;
        v ^= (v >> 31);

        set_ur_golomb(pb, v, k, limit, esc_len);
    }

    /**
     * write signed golomb rice code (flac).
     */
    static inline void set_sr_golomb_flac(PutBitContext *pb, int i, int k,
                                          int limit, int esc_len)
    {
        int v;

        v  = -2 * i - 1;
        v ^= (v >> 31);

        set_ur_golomb_jpegls(pb, v, k, limit, esc_len);
    }


}

#endif /* AVCODEC_GOLOMB_H */
